Sun sensors are commonly used on spacecraft for attitude determination. Since the position of the sun changes greatly with orbital location and season, sun sensors are usually required to operate over a wide angular range. As a result, sun sensors may occasionally view the sun illuminated earth (earthshine) as well as the sun, which can cause a significant error. This can be prevented to some degree by the use of baffles, but baffles restrict the field of view and may not be effective with large attitude offsets such as exists during acquisition.